Automotive driver's side airbag modules are customarily mounted in the steering wheel. The housing which contains the folded airbag is closed by a decorative cover which faces the driver. The cover is provided with weakened portions which form tearlines. Under the influence of the expanding airbag, the cover bursts along the tearlines so as to form one or more doors which open to release the airbag.
As the airbag cover is centrally mounted within the steering wheel, it provides a very convenient location for the installation of switches to control such functions as radio, air-conditioning, cruise-control, etc. However, it is also true that much of the airbag cover surface comprises an active region. By "active region" is meant those portions of the cover which are forcibly displaced upon rupturing of the tearlines to form the doors which release the airbag. As a result, it is important that any switches mounted within the active region be securely anchored so as not to part from the airbag cover material. One solution to this problem is disclosed in my prior U.S. Pat. No. 5,369,232. That patent describes a cover which has a thinned flexible area, behind which is mounted a membrane switch and a relatively rigid backup panel.
It is often desirable, for either aesthetic or functional reasons, to employ keypads for the control of function switches. Such a keypad would extend through an opening in the cover and might be, for example, slightly raised so as to be easily located by the fingers. A construction which employs such a switch is illustrated and disclosed in U.S. Pat. No. 4,934,735 of Embach. In that patent, however, the cover is actually in two parts. A switch is mounted between the upper wall of a "container" and the upper wall of a "cover", the keypad opening being provided in the cover. It would be desirable, however, to provide a construction wherein a separate keypad is mounted within a single piece cover, thereby simplifying construction and minimizing expense.
Accordingly, it is a primary object of the present invention to provide a keypad in a one-piece, driver's side airbag module cover. Other objects, features and advantages will become apparent from the following description and appended claims.